Camera module

ABSTRACT

An automatic focus apparatus for a camera module includes a voice coil motor and a driving unit. The voice coil motor includes a frame, a moving member with a lens, and a magnetic member. The magnetic member is positioned at a side wall of the moving member, the driving unit is positioned at a side plate of the frame. A magnetic field is generated by the driving unit and the magnetic member, the magnetic field drives the moving member with the lens to move, to achieve automatic focus.

FIELD

The subject matter herein generally relates to image-capturing.

BACKGROUND

Current mobile phones with a full screen require that a small sizedfront camera module. The camera module generally includes a lens, adriving unit, and a voice coil motor (VCM). The driving unit isseparated from the VCM and positioned outside the camera module. Thedriving unit is electrically connected to the VCM to drive the lens tomove.

The above described structure of the camera module is large and thus isnot conducive to a reduction of the overall volume. Furthermore, thedriving unit being placed outside the camera module is susceptible toenvironmental impact and affects an assembly of the camera module.

Therefore, there is room for improvement within the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with referenceto the figures. The components in the figures are not necessarily drawnto scale, the emphasis instead being placed upon clearly illustratingthe principles of the disclosure.

FIG. 1 is an exploded, isometric view of a camera module according to anembodiment of the present disclosure.

FIG. 2 is an assembled, isometric view of the camera module of FIG. 1 .

FIG. 3 is a block diagram of the camera module of FIG. 2 .

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures and components have notbeen described in detail so as not to obscure the related relevantfeature being described. Also, the description is not to be consideredas limiting the scope of the embodiments described herein. The drawingsare not necessarily to scale and the proportions of certain parts may beexaggerated to better illustrate details and features of the presentdisclosure.

The term “coupled” is defined as connected, whether directly orindirectly through intervening components, and is not necessarilylimited to physical connections. The connection can be such that theobjects are permanently connected or releasably connected. The term“comprising,” when utilized, means “including, but not necessarilylimited to”; it specifically indicates open-ended inclusion ormembership in the so-described combination, group, series, and the like.

FIG. 1 illustrates a camera module 300 according to an embodiment of thepresent disclosure. The camera module 300 includes an automatic focus(AF) apparatus 100 and a lens 200. The camera module 300 can adjust alocation of the lens 200 through the AF apparatus 100, thereby the lens200 can take a clear image.

The AF apparatus 100 includes a voice coil motor (VCM) 10 and a drivingunit 20. In this embodiment, the VCM 10 forms an open loop motor andincludes a frame 11, a moving member 13, a magnetic member 14, and ahousing 15. The moving member 13 is received in the frame 11. Themagnetic member 14 is positioned at a side wall of the moving member 13and corresponds to the driving unit 20. The housing 15 wraps around anoutside of the frame 11. The lens 200 is received in the moving member13 and partially exposed from the housing 15.

In this embodiment, the frame 11 is substantially rectangular. The frame11 includes a bottom plate 110 and at least one side plate. In thisembodiment, the frame 11 includes a first side plate 111, a second sideplate 112, a third side plate 113, and a fourth side plate 114. Thebottom plate 110 is substantially rectangular and configured to supportthe first to fourth side plates 111-114. The first side plate 111 andthe second side plate 112 are positioned parallel with each other. Thethird side plate 113 and the fourth side plate 114 are positionedparallel with each other. Each of the third side plate 113 and thefourth side plate 114 is perpendicularly connected to an end of thefirst side plate 111 and an end of the second side plate 112. The firstto fourth side plates 111-114 are all perpendicularly positioned at aperiphery of the bottom plate 110. The first to fourth side plates111-114 and the bottom plate 110 cooperatively form a first receivingspace 115.

In this embodiment, the bottom plate 110 defines a receiving slot 116.The receiving slot 116 is configured to receive a protecting pad 117.The protecting pad 117 is substantially in the form of a circular ring.A size of the protecting pad 117 is corresponding to the receiving slot116. The protecting pad 117 is used to prevent the moving member 13 fromdirectly contacting the bottom plate 110, that is, the moving member 13is isolated from the bottom plate 110 through the protecting pad 117.

In this embodiment, one of the first to fourth side plates 111-114defines an opening 118. In detail, the opening 118 is defined at thefirst side plate 111. The first side plate 111 further forms at leastone blocking portion 119. In one embodiment, the first side plate 111forms four blocking portions 119. The four blocking portions 119 arepositioned at four corners of the first side plate 111 adjacent to theopening 118.

In one embodiment, one of the first to fourth side plates 111-114further forms a clamping portion 120. In this embodiment, the clampingportion 120 is positioned at the third side plate 113.

The moving member 13 is accommodated in the first receiving space 115and resists the protecting pad 117. The protecting pad 117 is used toprevent the moving member 13 from directly contacting the bottom plate110 and reduce the friction when moving. In one embodiment, the movingmember 13 defines a second receiving space 130. In this embodiment, thesecond receiving space 130 is defined at a middle location of the movingmember 13 and configured to receive the lens 200. When the lens 200 isreceived in the second receiving space 130, the lens 200 moves togetherwith the moving member 13. The lens 200 can be moved to a presetlocation to achieve precise focusing.

The magnetic member 14 is positioned at a side wall of the moving member13 and corresponds to the first side plate 111. In this embodiment, whenthe magnetic member 14 moves, the moving member 13 is driven to move.

In one embodiment, the moving member 13 further forms at least onesliding groove 131. In this embodiment, the moving member 13 forms twosliding grooves 131. The two sliding grooves 131 are defined at ends ofa side wall of the moving member 13 where the magnetic member 14 ispositioned. The side wall of the moving member 13 defining the twosliding grooves 131 corresponds to or faces towards the first side plate111. Each of the two sliding grooves 131 is configured to receive a ball132. When the magnetic member 14 moves, the moving member 13 is moved.The balls 132 in the two sliding grooves 131 interlock with the movingmember 13 to reduce a friction of movement.

In this embodiment, a shape and a structure of the housing 15 arematched with the frame 11. The housing 15 is substantially a rectangularframe with one end open. By aligning the open end of the housing 15 withthe frame 11, the housing 15 covers the moving member 13 and the frame11. In one embodiment, the housing 15 defines a receiving hole 151 onone side of the housing 15 away from the open end. When the lens 200 isinstalled in the second receiving space 130, the lens 200 is partiallyexposed from the receiving hole 151.

In this embodiment, one side of the housing 15 further defines aclamping hole 152. The clamping hole 152 corresponds to the clampingportion 120. When the housing 15 covers the frame 11, the housing 15 isinstalled on the frame 11 by snapping the clamping portion 120 into theclamping hole 152.

In this embodiment, the driving unit 20 includes a circuit board 21, astorage unit 22, a driving chip 23, and a coil 24. The circuit board 21may be a printed circuit board (PCB). The circuit board 21 is positionedat the opening 118 of the first side plate 111. In one embodiment, thecircuit board 21 defines at least one notch 211. The at least one notch211 corresponds to the at least one blocking portion 119. For example,the circuit board 21 defines four notches 211. The four notches 211 aredefined at four corners of the circuit board 21. By aligning the fournotches 211 of the circuit board 21 to the four blocking portions 119and snapping the four blocking portions 119 into the four notches 211,the circuit board 21 is mounted on the first side plate 111 of the frame11.

The storage unit 22, the driving chip 23, and the coil 24 are allintegrated on the circuit board 21. The driving chip 23 is electricallyconnected to the storage unit 22 and the coil 24. The storage unit 22may be, but is not limited to, an electrically erasable programmableread only memory (EEPROM). The driving chip 23 is used to provide powerto the coil 24 and generate a magnetic field in the coil 24, therebydriving the magnetic member 14 to move. For example, when the coil 24 isenergized, a magnetic force is generated between the coil 24 and themagnetic member 14. The magnetic force drives the magnetic member 14 tomove relative to the frame 11, for example, the magnetic member 14 canbe moved up or down relative to the frame 11. Since the magnetic member14 is positioned on the moving member 13, the magnetic member 14 drivesthe moving member 13 and the lens 200 to move relative to the frame 11,thereby adjusting a focus of the lens 200.

As illustrated in FIG. 2 , in this embodiment, when assembling thecamera module 300, the circuit board 21 is firstly positioned on theside wall of the frame 11 in the above-mentioned manner. Next, themoving member 13 having the magnetic member 14 is accommodated in thefirst receiving space 115 and resists the protecting pad 117. The lens200 is accommodated in the second receiving space 130 of the movingmember 13. Finally, the housing 15 is mounted on the frame 11 and coversthe lens 200 and the moving member 13, and the lens 200 is partiallyexposed from the receiving hole 151.

As illustrated in FIG. 3 , the AF apparatus 100 further includes aprocessing unit 30. The processing unit 30 can be an image signalprocessor (ISP), a digital signal processor (DSP), or other processor.The processing unit 30 is electrically connected to the driving unit 20.

When the camera module 300 operates in an AF mode, the driving unit 20outputs a driving current from between zero to a maximum value. Then,the lens 200 can be driven by the driving unit 20 to move from anoriginal position to a maximum displacement. At this time, the lens 200automatically takes and saves pictures by the processing unit 30. Theprocessing unit 30 then calculates a modulation transfer function (MTF)value of each of the pictures to form an MTF curve and finds a maximumMTF value in the MTF curve through an algorithm. The processing unit 30further obtains a current value corresponding to the maximum MTF valueand instructs the driving unit 20 to provide that current (that is, thecurrent value corresponding to the maximum MTF value) to the VCM 10, sothat the lens 200 is stable on that imaging plane and an automatic zoomis achieved.

In this embodiment, the driving unit 20 is disposed on the side wall ofthe frame 11. A size of the camera module 300 is approximately 8.5*7.0MM. Compared with a size of a conventional camera module, for example,8.5*8.5 MM, the overall size of the camera module 300 is reduced by 1.5mm, thereby reducing the overall size of the camera module 300.

In this embodiment, the balls 132 serve to allow smooth movements whenthe moving member 13 moves relative to the frame 11. In this way, whenthe moving member 13 drives the lens 200 to move, a friction forcebetween the moving member 13 and the frame 11 is reduced, so that amoving distance is more accurate and long-term repeatability isenhanced.

In this embodiment, the camera module 300 can be applicable to, but isnot limited to, a front camera and/or a rear camera of an electronicdevice (not shown). The electronic device can be a mobile phone, atablet computer, a netbook, a computer, a smart wearable device, amonitoring equipment, a vehicle equipment, or other electronic device.

The camera module 300 has a simple structure. An overall volume of thecamera module 300 is reduced. The camera module 300 is provided withballs 132 instead of springs, thus eliminating gradations of drivingcurrent needed to overcome spring tension, power consumption is alsolowered. Additionally, the camera module 300 reduces the number ofmagnetic members 14 and does not include a spring. Thus, unnecessarydamping effect of the spring is completely eliminated, the focusingaccuracy of the camera module 300 is improved and a focusing speed isfaster.

It is believed that the embodiments and their advantages will beunderstood from the foregoing description, and it will be apparent thatvarious changes may be made thereto without departing from the scope ofthe disclosure or sacrificing all of its advantages, the exampleshereinbefore described merely being illustrative embodiments of thedisclosure.

What is claimed is:
 1. A camera module comprising: a lens; and anautomatic focus apparatus comprising: a frame; a moving member receivedin the frame and configured to receive the lens; a magnetic memberpositioned at a side wall of the moving member; and a driving unitpositioned at a side plate of the frame and corresponding to themagnetic member; wherein each of the moving member and the lens is movedby a magnetic field between the driving unit and the magnetic member;wherein the frame comprises four side plates, one of the four sideplates defines an opening, the driving unit comprises a circuit board,at least one blocking portion is formed on the side plate of the framehaving the opening, the circuit board defines at least one notchcorresponding to the at least one blocking portion, the circuit board ismounted on the side plate having the opening by snapping the at leastone blocking portion into the at least one notch; and wherein the framefurther comprises a bottom plate, the bottom plate defines a receivingslot, the receiving slot is configured to receive a protecting pad, andthe protecting pad is configured to prevent the moving member fromcontacting the bottom plate.
 2. The camera module of claim 1, whereinthe frame further comprises at least one side plate, the at least oneside plate is perpendicularly positioned at a periphery of the bottomplate, the bottom plate and the at least one side plate cooperativelyform a first receiving space, the moving member is received in the firstreceiving space.
 3. The camera module of claim 2, wherein the drivingunit is positioned at the opening.
 4. The camera module of claim 1,wherein the driving unit further comprises a driving chip and a coil,the driving chip and the coil are positioned at the circuit board, thedriving chip is electrically connected to the coil to a driving currentto the coil, when the coil is energized, the magnetic field is generatedbetween the coil and the magnetic member and drives the magnetic memberto move relative to the frame.
 5. The camera module of claim 4, whereinthe side wall of the moving member where the magnetic member ispositioned defines at least one sliding groove, a ball is received inthe at least one sliding groove, when the moving member moves relativeto the frame, the ball interlocks with the moving member to reduce afriction of movement.
 6. The camera module of claim 1, furthercomprising a housing, wherein the housing is mounted on the movingmember and the frame.
 7. The camera module of claim 6, wherein thehousing defines a receiving hole, the receiving hole is configured tomake the lens partially exposed from the receiving hole.
 8. The cameramodule of claim 6, wherein the frame comprises a clamping portion, thehousing defines a clamping hole, the housing is mounted on the frame bysnapping the clamping portion into the clamping hole.
 9. The cameramodule of claim 1, further comprising a processing unit, wherein theprocessing unit is electrically connected to the driving unit, when thecamera module operates in an automatic focus mode, the driving unitoutputs a driving current from between zero to a maximum value, the lensis driven by the driving unit to move from an original position to amaximum displacement, the processing unit instructs the lens to captureimages, the processing unit saves images captured by the lens,calculates a modulation transfer function (MTF) value of each of theimages to form an MTF curve and finds a maximum MTF value in the MTFcurve through an algorithm, the processing unit further obtains a valueof an electric current corresponding to the maximum MTF value andinstructs the driving unit to provide the electric current to drive themoving member to move.
 10. A camera module comprising: a lens; and anautomatic focus apparatus comprising: a frame; a moving member receivedin the frame and configured to receive the lens; a magnetic memberpositioned at a side wall of the moving member; and a driving unitpositioned at a side plate of the frame and corresponding to themagnetic member; wherein each of the moving member and the lens is movedby a magnetic field between the driving unit and the magnetic member;wherein the camera module further comprises a housing, the housing ismounted on the moving member and the frame; wherein the frame comprisesfour side plates, one of the four side plates defines an opening, thedriving unit comprises a circuit board, at least one blocking portion isformed on the side plate of the frame having the opening, the circuitboard defines at least one notch corresponding to the at least oneblocking portion, the circuit board is mounted on the side plate havingthe opening by snapping the at least one blocking portion into the atleast one notch; and wherein the frame further comprises a bottom plate,the bottom plate defines a receiving slot, the receiving slot isconfigured to receive a protecting pad, and the protecting pad isconfigured to prevent the moving member from contacting the bottomplate.
 11. The camera module of claim 10, wherein the frame furthercomprises at least one side plate, the at least one side plate isperpendicularly positioned at a periphery of the bottom plate, thebottom plate and the at least one side plate cooperatively form a firstreceiving space, the moving member is received in the first receivingspace.
 12. The camera module of claim 11, wherein the driving unit ispositioned at the opening.
 13. The camera module of claim 10, whereinthe driving unit further comprises a driving chip and a coil, thedriving chip and the coil are positioned at the circuit board, thedriving chip is electrically connected to the coil to a driving currentto the coil, when the coil is energized, the magnetic field is generatedbetween the coil and the magnetic member and drives the magnetic memberto move relative to the frame.
 14. The camera module of claim 13,wherein the side wall of the moving member where the magnetic member ispositioned defines at least one sliding groove, a ball is received inthe at least one sliding groove, when the moving member moves relativeto the frame, the ball interlocks with the moving member to reduce afriction of movement.
 15. The camera module of claim 10, wherein thehousing defines a receiving hole, the receiving hole is configured tomake the lens partially exposed from the receiving hole.
 16. The cameramodule of claim 10, wherein the frame comprises a clamping portion, thehousing defines a clamping hole, the housing is mounted on the frame bysnapping the clamping portion into the clamping hole.
 17. The cameramodule of claim 10, further comprising a processing unit, wherein theprocessing unit is electrically connected to the driving unit, when thecamera module operates in an automatic focus mode, the driving unitoutputs a driving current from between zero to a maximum value, the lensis driven by the driving unit to move from an original position to amaximum displacement, the processing unit instructs the lens to captureimages, the processing unit saves images captured by the lens,calculates a modulation transfer function (MTF) value of each of theimages to form an MTF curve and finds a maximum MTF value in the MTFcurve through an algorithm, the processing unit further obtains a valueof an electric current corresponding to the maximum MTF value andinstructs the driving unit to provide the electric current to drive themoving member to move.